Electrifying Heating: Trade-offs between Comfort, Cost, and Electricity Distribution System Load

In cold climates, widespread electrification of space heating is likely to result in a sharp increase the peak demand experienced by the electricity distribution system. In response, utilities may impose dynamic (e.g., time of use) tariffs, which have been shown to disproportionately raise electricity bills for vulnerable populations (e.g., people of color, the disabled, and the elderly). Already, 10-15% of U.S. households keep their homes and unhealthy temperatures due to economic constraints. Unless managed carefully, electrification may make the problem worse. In the proposed research, we will quantify the trade-off that typical U.S. single family homes in different parts of the country might face between comfort and peak electricity demand at local electricity distribution substations. To do so, we will model the hourly energy use of U.S. single-family homes using the National Renewable Energy Laboratorys ResStock database and EnergyPlus model. We will build a reduced complexity model (RCM) that relates heating input with indoor temperature. We will couple this RCM with a model of the heat pumps temperature-dependent coefficient of performance. We will develop an optimization model that minimizes a weighted sum of discomfort and substation-level peak electricity demand. We will define discomfort as cumulative difference between desired and observed indoor temperatures, summed over all the modeled houses in a city over all 8760 hours in the year. In a second version of this model, we will assume that the house faces a dynamic electricity price, including a component that depends on the houses peak demand. We will run a version of our optimization model in which the objective function is a sum of discomfort and cost. By varying the weights assigned to each component of the objective function, we will be able to quantify the trade-off that the current housing stock faces between cost, peak electricity demand, and potential discomfort. We will model 50+ cities in different U.S. climate zones and in each city model 200+ archetypical homes representing the citys housing stock. We will model current and projected future temperatures. This work will form the foundation for an extensive exploration of strategies (e.g., targeted weatherization subsidies) to ensure an equitable transition to electric heating.